Java - Increment (++) and Decrement (--) Operators
What are Increment (++) and Decrement (--) Operators?
The increment operator (++) increments a variable of numeric data type value by 1.
The decrement operator (--) decrements the value by 1.
The rules on increment operator ++ can be applied to decrement operator --.
Increment ++ Operators
In the following code,
int i = 100;
To increment the value of i by 1, you can use one of the four following expressions:
i = i + 1; // Assigns 101 to i i += 1; // Assigns 101 to i i++; // Assigns 101 to i ++i;
The increment operator ++ can be used in a more complex expression as
int i = 1; int j = 5; j = i++ + 1;
Demo
public class Main { public static void main(String[] args) { int i = 1; //from w ww . j a v a2 s. com int j = 5; j = i++ + 1; System.out.println(j); } }
Result
two kinds of increment/decrement operators
There are two kinds of increment/decrement operators:
- Post-fix increment operator, for example, i++. When ++ appears after its operand, it is called a post-fix increment operator.
- Pre-fix increment operator, for example, ++i. When ++ appears before its operand, it is called a pre-fix increment operator.
The post-fix increment uses the current value of its operand first, and then increments the operand's value.
The pre-fix increment increments the operand's value, then uses the current value of its operand first,
Demo
public class Main { public static void main(String[] args) { int i = 1; /*from www .j a v a 2 s . c om*/ int j = 0; j = i++ + 1; System.out.println(j); System.out.println(i); i = 1; j = 0; j = ++i + 1; System.out.println(); System.out.println(j); System.out.println(i); } }
Result
